Ports, harbors and other waterfronts, waterways, and off-shore structures are vulnerable to attack by small watercraft, i.e., vehicles, vessels or crafts that move across or through water, such as a speedboat. These watercraft are common in the water and are used for many purposes such as for pleasure, recreation, physical exercise, commerce, transport of people, and goods. It is difficult to distinguish recreational watercraft from a hostile watercraft, such as, a watercraft loaded with explosives that is designed to detonate and cause harm to people, structures, and other watercraft. A small hostile watercraft can potentially slip into a harbor or other waterfront structure unnoticed or otherwise undeterred and cause severe damage to people and property.
Near shore, port, and off-shore barriers are known. Examples of such barriers are described in U.S. Pat. Nos. 4,135,467, 6,681,709, 6,843,197, and 7,401,565. These port security barriers (PSB or PSBs) are comprised of modular, floating barrier sections. Known PSB systems include a capture net and net support structure which operates to stop waterborne craft and prevent entry into a port. Prior art floating PSB systems are formed in barrier sections with a barrier net positioned atop spaced apart floating pontoons (see, FIG. 1, Prior Art). Longer floating PSB systems are multi-sectional, formed in approximately 50 foot sections, with individual barrier sections being linked together longitudinally with a connector assembly, which secures the individual barrier sections together. Over the span of a mile, there may be as many as 100 connecting barrier sections, and 100 corresponding connector assemblies. The cost of the connector assembly adds significant cost to the overall cost of the barrier system. As each connector assembly can cost between $3,000 to $5,000, this can add a cost of $300,000 or more per mile to the overall cost of the barrier. In addition, these multi-sectional floating PSB systems suffer the disadvantage of being subject to damage in the wind, waves, currents, storms and other harsh environmental conditions in unprotected areas or open ocean. When multi-sectional floating PSB systems are subject to environmental energies, such as storms, high wind or waves, the environmental energies can tip a barrier section of the multi-sectional floating PSB, twisting the elongated fence structure, making it vulnerable to threat. In addition, as the individual barrier sections of the prior art multi-sectional floating PSB systems are linked together with a connector assembly (approximately every 50 feet), there are additional replacement and maintenance costs for each connector assembly.
In addition, waterways, such as dams, rivers, inlets, channels and canals can become obstructed with debris, causing damage, time delay and associated cost to clear the debris obstruction. Floating debris can pass between the barrier sections (unless additional barriers to close the gap are installed), and/or under the barrier, interfering with gate systems, dams, and other valuable infrastructure.
Therefore, there is a need for an improved barrier system that is effective against high speed watercraft, and is resistant to environmental energies and subsequent damage to the barrier from barrier tipping, and corresponding increased maintenance costs. There is also a need for an improved barrier system that can block floating debris, and is easily modified to provide protection from subsurface debris.